Interventional medicine is the collection of medical procedures in which access to the site of treatment is made through one of the patient's blood vessels, body cavities or lumens. For example, electro-physiology mapping of the heart is most often performed using a catheter which may be inserted into a patient's arterial system through a puncture of the femoral artery in the groin area. Other interventional medical procedures include assessment and treatment of tissues on the inner surfaces of the heart (endocardial surfaces) accessed via peripheral veins or arteries, treatment of vascular defects such as cerebral aneurysms, removal of embolic clots and debris from vessels, treatment of tumors via vascular access, endoscopy of the intestinal tract, etc.
Interventional medicine technologies have been applied to manipulation of instruments which contact tissues during surgical procedures, making these procedures more precise, repeatable and less dependent of the device manipulation skills of the physician. Some presently available interventional medical systems for directing and manipulating the distal tip of a medical device by actuation of the distal portion of the device use computer assisted navigation and an imaging system for providing imaging of the device and blood vessels and tissues. Such systems can control the navigation of a medical device, such as a catheter, to a target destination in an operating region using a computer to orient and guide the distal tip through blood vessels and tissue. In some cases, when the computed direction for reaching the target destination is determined and the medical device is extended, it is desired to establish sufficient contact of the medical device with the intended target location on the three dimensional tissue surface. Adequate contact with the tissue surface within the subject body is important, for instance, in the analysis and treatment of cardiac arrhythmias. A method is therefore desired for controlling movement of a medical device that will establish adequate contact with the target tissue surface, estimate such contact force and will allow for treatment of the targeted area.